[백준/BOJ] 10828. 큐 [Silver 4]

10828. 큐

문제출처 : https://www.acmicpc.net/problem/10845

code

#include <iostream>
#include <queue>
using namespace std;

int main()
{
    int N, push_num;
    cin >> N;
    queue<int>q;
    string cmd;

    for (int i = 0; i < N; i++)
    {
        cin >> cmd;
        if (cmd == "push")
        {
            cin >> push_num;
            q.push(push_num);
        }
        else if (cmd == "pop")
        {
            if (q.empty())
                cout << -1 << endl;
            else
            {
                int x = q.front();
                q.pop();
                cout << x << endl;
            }
        }
        else if (cmd == "size")
            cout << q.size() << endl;
        else if (cmd == "empty")
        {
            if (q.empty())
                cout << 1 << endl;
            else
                cout << 0 << endl;
        }
        else if (cmd == "front")
        {
            if (q.empty())
                cout << -1 << endl;
            else
                cout << q.front() << endl;
        }
        else if (cmd == "back")
        {
            if (q.empty())
                cout << -1 << endl;
            else
                cout << q.back() << endl;
        }
    }

    return 0;
}

단순 큐 구현문제다.